The present invention relates to motor vehicles and other machines or assemblies which employ friction clutches. More particularly, the invention relates to improvements in means for operating friction clutches in motor vehicles and in the manner of assembling the operating means with friction clutches.
A friction clutch normally comprises a support (e.g., a housing or cover) which is provided with or carries a seat for a diaphragm spring serving to bias a pressure plate against a clutch plate so that the latter can be urged against the flywheel on the crankshaft of an internal combustion engine to drive the input shaft of a change-speed transmission when the engine is on. The means for engaging or disengaging the clutch normally comprises an actuator which engages the innermost portions of radially inwardly extending prongs forming part of the diaphragm spring. A pull-type friction clutch is constructed in such a way that the pressure plate engages the diaphragm spring radially inwardly of the seat on the support. In such friction clutches, the actuator must be connected with the innermost portions of the prongs so that it can move the end portions axially of the diaphragm spring in a first direction to engage the clutch as well as in a second direction (counter to the first direction) in order to release the clutch.
A drawback of presently known pull-type friction clutches for use in motor vehicles is that their installation in and their removal from the power train between the crankshaft of an internal combustion engine and the input shaft of the change-speed transmission constitute tedious and time-consuming operations. As a rule, the actuator is secured to the diaphragm spring before the clutch is operatively connected with the input shaft of the transmission, and the means for moving the actuator axially of the diaphragm spring is assembled with the transmission before the latter is connected with the output element (such as a clutch plate) of the clutch.